50 



FUNGI. 



the threads are branched, but the spores are collected in clusters 

 usually, and are moreover septate. In other genera similar 

 distinctions prevail. These two groups of black moulds and 

 white moulds are the noblest, and contain 

 the largest number of genera and species 

 amongst the Hyphoviycetes. There is, how- 

 ever, the small group of Isariacei, in which 

 the threads are compacted, and a semblance 

 of such hymenomycetal forms as Clavaria 

 and Pterula is the result, but it is doubtful 

 if this group contains many autonomous 

 species. In another small group, the Stil- 

 bacei, there is a composite character in the 

 head, or receptacle,* and in the stem when 

 the latter is present. Many of these, again, 

 as Tubercufaria, Yolutella, Fusarium, &c., 

 contain doubtful species. In Sepedoniei and 

 FIO. so.-PenirMium char- Trichodermacei, the threads are reduced to a 



tarum, Cooke. 



minimum, and the spores are such a dis- 

 tinctive element that through these groups the HypJiomycetes 

 are linked with the Coniomycetes. These groups, however, are not 

 of sufficient size or importance to demand from us, in a work of 

 this character, anything more than the passing allusion which 

 we have given to them. 



We come now to consider the structure in the Sporidiifera, in 

 which the fructifying corpuscles or germs, whether called spores 

 or sporidia, are generated within certain privileged cysts, usually 

 in definite numbers. In systematic works, these are included 

 under two orders, the Physomycetes and the Ascomycetes. The 

 former of these consists of cyst-bearing moulds, and from their 

 nearest affinity to the foregoing will occupy the first place. 



PHYSOMYCETES include, especially amongst the Mucorini, many 

 most interesting and instructive species for study, which even 

 very lately have occupied the attention of continental mycolo- 

 gists. Most of these phenomena are associated more or less 

 with reproduction, and as such will have to be adverted to again, 

 * Cooke, " Handbook of British Fungi," vol. ii. p. 552. 



